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regmap updates in 3.4

Things are really quieting down with the regmap API, while we’re still seeing a trickle of new features coming in they’re getting much smaller than they were.

Support for padding between the register and the value when interacting with the device. This is required by some devices with high speed control interfaces in order to give the device time to get the values ready.

Support for applying register updates to the device when restoring the register state. This is intended to be used to apply updates supplied by manufacturers for tuning the performance of the device (many of which are to undocumented registers which aren’t otherwise covered). For want of a better term this feature is known as a patch.

Support for two bit address, six bit value registers contributed by Wolfram Sang.

Support for multi-register operations on cached registers contributed by Laxman Dewangan.

Some additional diagnostics available via debugfs for the cache state.

Support for syncing only part of the register cache, useful for devices with power domains or sub devices which can be reset independently.

Stubs and parameter query functions intended to make it easier for other subsystems to build infrastructure on top of the regmap API.